The treatment and/or cure of cancer has been intensely investigated culminating in a wide range of therapies. Cancer has been typically treated with surgery, radiation and chemotherapy, alone or in conjunction with various therapies employing drugs, biologic agents, antibodies, and radioactive immunoconjugates, among others. The common goal of cancer treatment has been, and continues to be, the elimination or amelioration of cancerous tumors and cells with minimal unpleasant or life-threatening side effects, due to toxicity to normal tissues and cells. However, despite efforts, these goals remain largely unmet.
Even where effective non-invasive drug therapies have been developed, patients having solid malignant tumors and hematological malignant disorders often develop multidrug resistance. Current therapies involve the administration of increased dosages of the anticancer drug or drugs to which the cancer cells have become resistant and/or administration of agents designed to reverse drug accumulation defects in drug resistant cells. However, these therapies are limited by risk of toxicity to the patient.
Alpha- and beta-acids, derived from hops, possess the ability to inhibit the growth of microorganisms. Some of these acids have been used as antibiotic and antifungal agents. In addition, alpha acids (also known as humulons) have been shown to inhibit the tumor promoting effect of 12-O-tetradecanoylphorbol-13-acetate in mice (Yasukawa et al., Oncology 52:156-158 (1995)). Colupulone has been reported to be active against Hela cells, CEM leukemia cells, and adriamycin- and vinbiastin-resistant CEM cells (Mannering et al., Food, Nutrition and Chemical Toxicity, Parke et al., eds, Smith Gordon, G. B. (1993) at ch. 28).
Thus, a need exists for new and effective drug therapies for treating cancer which have minimal side effects and are also effective against multidrug resistant cancer cells.